Mitsubishi Meldas 520 4th axis direction parameters

Hello,

I am looking for some help with my Hartford 850 vmc, with Meldas 520am control, 1998.
I have a golden sun 4th axis that came with the machine that I have only been able to use as an positional indexer so far.
I am now trying to run some simple simultaneous toolpaths (wrapped 2d contour in F360 to finish a large external groove on a shaft)
I have modified the post processor to output the correct code but the 4th axis will only move in one direction (Clockwise when looking straight onto the 4th axis plate which is mounted on the right hand side of the table in line with the x axis)

Can anyone help with correcting this? Is there a parameter I can change which will allow the 4th axis to take the shortest path (IE the programmed direction) instead of forcing a clockwise direction every time.

Any help would be appreciated, this will save me from having to set these shafts up back in the lathe to finish the grooves and keep everything concentric to the other drilled features in this set up.